1. Field of the Invention
The present invention relates to a transportable bed or platform for supporting various constituents of industrial equipment, which bed is adapted to be used in the construction of industrial equipment wherein the constituents of the said industrial equipment are built on one or more beds at the factory so as to form one or more unit structure sections of the industrial equipment, transporting the unit structure section or sections to the installation site and installing them along with the beds on a foundation, thereby to complete the construction work.
2. Description of the Prior Art
In building industrial equipment or plants of various types by a conventional technique, the component parts of the equipment are separately fabricated at a factory or factories, transported to the installation site, installed on foundations prepared at the site and, then, connected to each other by piping and/or electric wiring to complete the construction of the total assembly of the equipment.
In view of the current tendency toward more complicated construction of the individual components themselves and the connections therebetween, it is quite troublesome and inconvenient in all the aspects of transportation, storing, assembling and testing, to complete the construction by employing such steps as dividing the large components into a plurality of sub-components, packing and transporting the sub-components and small constituents in separate packages, sorting and storing them at the installation site for more efficient assembling in accordance with the progress of the construction work, assembling and combining the components and then testing the completed installation using engineers of various technical fields who are sent to the installation site from the factory. Such a construction procedure requires a large number of engineers and workers and a highly systematic organization, if the contract terms are to be strictly fulfilled.
This problem is serious especially when the construction is performed in an under-developed region, because it is difficult to maintain acceptable communication and transportation systems for the frequent coming and going of engineers, living conditions such as dormitories, as well as electric power and water resources. In addition, weather conditions are often severe in under-developed regions, which makes it extremely difficult to build and maintain proper living conditions for a large number of persons engaged in the construction work for a long time.
The demand for such construction work in these under-developed regions is, however, increasing.
To comply with this demand, it has already been done to modify a large existing vessel so that it will accomodate a large plant, or to build the entire plant on a specifically designed floating base. The vessel or the floating base is towed to the site across the sea, and it is then fixed or moored whereby to function as a complete installation of the industrial equipment situated in a body of water at the site.
It has also been proposed to carry out the construction by the steps of building the entire industrial equipment on a flat bed at a factory where construction equipment and skilled workers are available, transporting the built industrial equipment along with the bed to a site on land, or fixing the equipment together with the bed to a floating base for sea transportation and then landing and transporting it to the land site, so that the equipment can be used at the land site or afloat.
According to the latter-mentioned way, when the industrial equipment to be constructed is huge, it is divided into a plurality of sections. Each section is built on its own flat bed, and the individual beds are transported to the site. Then, the sections are connected to one another at the site to complete the desired assembly of industrial equipment.
This method of construction will be described in more detail, with reference to an industrial chemical plant, by way of example, in which the connections of the component parts are critical. It is possible to remarkably shorten the construction time by reducing the amount of on-site work, by designing and building the chemical plant in a plurality of separate blocks or sections, transporting the sections to the site separately and combining them at the site to form a complete plant. In this type of construction, it is necessary to make the size of each section as large as possible, so as to reduce the number of sections as much as possible, and to work out suitable measures for ensuring a safe and efficient sea transportation and precise installation at the site.
In some cases, the sections of the equipment built at the fabrication site on flat beds, including constituent machinery, piping and wiring, will weigh 500 tons or more. In order to support this heavy weight and to ensure safe transportation of the same for many days, it is necessary to fabricate beds of very high mechanical strength, employing a large quantity of steel structural members of large cross-sectional areas and/or large H-cross-sectioned steel beams. For information purposes, it is to be noted that, in some cases, the constituent subassembly to be built on a single bed has a height of about 30 m, a width of 5 m and a weight of about 300 tons.
In building the section or sections of the equipment on the bed or beds, first the bed itself is assembled at the factory, on a temporary foundation, and then the components are built on the bed or beds. The completed subassembly and bed is then lifted for mounting on the vehicle for transportation. Thus, the bed has to have three different weight-balancing points so that it can be stably supported on the temporary foundation, on the lifting means and also on the vehicle. This requirement makes the design of the bed more difficult because of the complicated strength considerations, resulting in a further increased strength of the bed.
When the built-up subassembly of the equipment on the bed is delivered from the ground transportation vehicle to the vessel along with the bed, for the purpose of sea transportation, the bed is mounted on a temporary foundation prepared on the vessel. This temporary foundation on the vessel must also be large and strong enough to withstand large force moments caused by the pitching and rolling of the vessel as it travels across the sea.
In order to prevent the flat bed of the equipment section on the deck of the vessel from slipping along the deck surface, the bed has to be provided at its outer side with fastening means through which the bed is fastened to the deck. These fastening means are usually provided in pairs on the respective sides of the bed and, therefore, the total breadth of the bed is increased inconveniently. To accommodate this increased breadth of the bed, the vessel must also have a sufficiently large breadth.
In other words, the bed is designed to have a breadth which is reduced by a length corresponding to the total breadth of the two large fastening means which are provided at both sides of the bed. Consequently, the full breadth of the vessel or the full loading capacity of the vessel cannot be effectively utilized. At the same time, it is quite disadvantageous that the breadth of the bed is reduced due to the provision of the fastening means which are necessary only during the short period of transportation, but are unnecessary during the long time use after the final installation site.
After the transportation, in installing the section of the equipment on the foundation prepared at the installation site, it is necessary to move the bed on the foundation slightly, in order to achieve a proper location of the constituent machinery, in order that the machinery can be connected to the associated machinery of other equipment sections or to other machinery not on sections, precisely through piping and electric wiring.
When a flat bed is used, a large horizontal thrust is applied on the surface of the foundation, as a result of the horizontal movement of the contacting lower surface of the flat bed.
It is, therefore, necessary to prepare a large foundation having a high strength, because otherwise the fine adjustment of the bed position cannot be achieved. If the fine adjustment of the installation position is not correctly achieved, the number of connections at the boundaries of the equipment sections is drastically increased.